Flushing composition for engine lubricating systems



Patented May 24, 1949 FLUSHING coMrosrrioN FOR ENGINE LUBRICATING SYSTEMS} John D. Morgan, South Orange, and Russell E. Lowe, East Orange, N. 3., assignors to Cities Service Oil Company, New York, N. Y., a cor poration of Pennsylvania N Drawing. Application July 8, 1946, Serial No. 682,157

1 Claim.

' safely run at normal -This invention relates to improvements insolvent compositions, and more particularly to products of this general class for use in flushing out engine lubrication systems at more or less regular intervals.

The oil composition disclosed in Patent 2,301,918 has proven to be an excellent solvent for resins, varnishes, and other gummy residues of petroleum oil, and accordingly, much more exfective than the light bodied fuel oils which are conventionally employed for flushing the crankcases of automobile engines and the like. Its action upon sludge deposits, however, leaves something to be desired. While this solvent readily dissolves the resinous matter which binds the sludge to the engine walls, and thus allows the latter to break away, it has little or no power to disperse this heavy matter. In a large majority of cases the loosened sludge is broken up by me chanical agitation in the crankcase to the point where it may be circulated with the flushing composition and ultimately drained from the engine with that liquid. Occasionally, however, sludge will be brought down in such volume that mechanical agitation does not sumce to break it up, with the result that the highly viscous matter is drawn around the oil strainer to interfere with proper oil circulation. We have observed,

for example, that it is somewhat hazardous to use this composition in automobile engines which have been driven for more than 35,000 miles with only conventional kerosene oil flushing. In such to considerable likelihood that the oil circulation system may be completely blocked, with the corresponding possibility that the bearings may be burned, cylinders scored, etc. before the stoppage can be cleared.

The principal object of the invention is to provide a flushing composition which is a highly effective solvent for removing oil varnishes, resins, and similar gummy deposits, and is at the same time well able to disperse sludge accumulations so that this heavy matter may flow with the solvent and ultimately be drawn from the engine in suspension in that light-bodied liquid.

' It is a further object of the invention to provide a composition of the foregoing kind which has the ability to work its Way into close fitting bearings, around piston rings, and into other crevices to dissolve oil residues, and. which will a degree such as will permit the engine to be 2 idling speeds during the course of the cleaning and flushing operation.

Yet another object of the invention is to provide an inexpensive and highly efficient solvent for cleaning machine parts and other general utility purposes.

Our preferred composition for use in passenger automobiles and in other engines which are subject to the same general type of intermittent service at varying loads, is made of the following ingredients in about the proportions indicated.

Per cent by volume Ortho dichloro benzene 49.5 Cresylie acid l9 Naphtha E. P. agent 1 Magnesium wax acids soap 0.5

In preparing this composition we make use of a commercial grade of ortho dichloro benzene, a cresylic acid of about 97-99 per cent purity, and a high flash naphtha having a boiling range of about 163-1'77 F. The extreme pressure agent serves of course to impart load carrying ability to the composition. For this purpose we prefer to use a per cent sulphurized tricresyl or tributyl phosphite, in about the proportions indicated. Good results can also be gotten by the addition of from 1 to 2 per cent of chlornaphtha Xanthate, chlcro methyl stearate, or other well-known film strength improver. The last ingredient serves the dual purpose of acting as a detergent-dispersant, and as a neutralizer to hold the pH of the composition at a value of about 8. A magnesium soap which is entirely suitable for use in this composition may be prepared as follows: Molten paraflin wax (M, P. 122-126 F.) is blown with excess air for a period of from 18 to 30 hours to carry out an oxidation reaction at a temperature of from 300-315' F. or thereabouts, to yield a mixture of wax acids together with ketones, alcohols and esters, and

other partial oxidation products, and some un-- reacted hydrocarbons. This crude mixture, having a neutralization number of about 66 and a saponification number of around 130, is then treated with naphtha, which preferably is of predominately parafiinic character, in a ratio of about 10:1 by volume for the purpose of separating out naphtha-insoluble hydroxy acids and other oxidation products. The naphtha solution may then be treated with zinc chloride (preferably of about concentration) or phosphoric acid concentration) or both, to precipi-'-' tate naphtha soluble hydroxy acids and some mutually soluble oxidation products. Upon completion of this separatory treatment the naphtha solution may be flash distilled to yield a mixture consisting principally.- of. carboxlllic wax. acids together with a. small; proportion of) ketones, esters, alcohols, possibly lactides and lactones, etc. which are suitable for reaction with magnesium. oxide to yield the desired soap. In general, we prefer to carry out this latter reaction by heati-ng; the wax acids to a temperature of from 290 300 F., and by then adding the Inasnesiumoxideate. rate such as to prevent thetemperaturefrom. rising much above 315 F., thereby avoidin -Joseof the lighter solvent constituents of the acid mixture, and excess foaming. The. soap Oi. this reaction may contain from about 1.2 to 8.100%, 3.5% by weight of magnesium.

The flash point of the preferred composition.- is about 160 F.well above that of kerosene and other c nventional flushing oilseudwflhin l: of soanderdsafeti'. spec fica ions. It. s of furth r notethat. t e: action. of the comb sition upon copp r is. substantially nil... e relished strip of this; material. showed c r rosion after being held in the solventtera period. 1 sixv hours. at a emperature; or r80 E. in. a standard oppe c rros on. est. The xtreme pressure charac erist s. of. the solvent were-tested: n a standard four ball. ma hin the results showing, a. steady rise in; friction; with increasin load, and a maximum of 14 millimeters at 500 pounds gauge, followed by seizure. In this respect the new composition is exceptionally good, andby comparison considerably better than. conventional flushing oils;

The properties which have been discussed above. are indications of' the suitability of the compo.- sition for use ininternal combustion engines. 'libusi s fiash point. ishighaenousb tomeeosaiety requirem nts: and. its P, nroperti ar u h. astoinsure a equ te lub lcationgdurins theilushlug. operation. The solvent and detergent. DIOD rties: of thee Imp sition were thorou hly test d: on pe role m varnish, and on heavy crankcase slud e. he: first in tame we. prepared: a l er of: samples of. pe roleum varnish. by baking: ubricating l on. steel. es strips at. tempera im of. 49.0 .F. ion pe iods of; timesuflicient: to

formali m, resinous coat n s; Thc etest. strips;

wer the im rsed n our solvent-for en. min utes. atthe: end of: wh ch time the-gummy resie duesw r so. softasto be easily wiped on. It; will be appreciated. of course. that; the temperarue.- at. whi h this: test; was: ca ried? out; nemeln E2. was much lower than that; ncountered; a nonnal: eng ne operation. and. that. the: testner od' wasllkewisesh rtcr. than the normalzfiusba. naooe etion. In addit on. wound that by si'oshe s: he l q id aroun hetesbstr ns; in airman nen s me hat omparable to: that. which. oc urs in an. enginerenkcase during: a. flushing; operas. ti n, thesof ened varni h? was: completely washed: wesfllh action o the solvent onierankcase slud e was. te ted in the follo ing ere. section or m sh copper. s reen: o one; in h w dth. horough y impregnated: tor one inchof. its length. with. the heavy sludge taken. from. the crankcase of. a. delivery truck after a long; period Of. .dayi .v andday. outopereti m. Ihisstripwes ben hung n a test u filled. with. ourcomoosition for. a... period, of thirty minu es. at. a temperal lllle Qi 7.5? E. It is of Particular not tbattbecombo sition. wa n agi ate but. was. purposely held. doing, range. are. h gh y. usefulinthe. decreasin 4 in a quiescent state. At the end of that time it was observed that the screen had been stripped clean, and that the sludge was thoroughly disparsed and suspended in the liquid flushing com- Position...

The results of, the foregoing. laboratory tests have been fully confirmed in actual practice. In these practical demonstrations on both passenger cars and trucks, we have followed the conventional practice of draining oil the charge of dirty oil, refilling the crankcase with a suitable volume of solvent, of then running the engine; for, a. period of 15-20 minutes at fast idling speed, followedby a. draining of the flushing composition. During the course of such an operation, the highly solvent liquid was actively circulated through the lubrication system and was flushed over the bearings, pistons, and cylinder walls to act upon any gummy oil residues that were present. In this connection it is of parioular. no e. tha the omposi ion is.-1ight-bodied an has high: etratmeb wer so that. it readi y worked its way through the beari gs, around. Elston: ri gs and: between: her c ose-fitting: P rts: where oil residues are normally found. At thesame t me the solvent was.- thoroughly churned min the orankcaseand sloshed over the engine wa1ls. the crank shafilz, camshaft, and o her parts. so that it might, loosen any sludge clinging. to their, surfaces. The action oi he: composition. the highly viscous matter. which. was thus. brought down. appeared to be both. solvent and. dlspersent in character. Thus the soluble. per-- tionsv of the sludge were. dissolved, and the. in.

. soluble por iondisnersedand suspended. in. the

liquid. It was observed. that the dispersed. slud material flowed with the l quid and. showed no tend ncy to. sett e. out; that. it. readily pass dthrough the oil strainer. and lube. lines, and was. drawn from. he crankcase. with. the composition at. the end of the flushin operation. In. no in.- ance. have. we encountered. a sludge which will resist, dispersion by our composition. and retain its viscous. character so. as to. give rise. to the possibility of. strainer. and oil. line clogging. On. the. contrary, we find. that this. solvent may be. u edwith entire saiety in eng nes. in which sludge. has a cm ula ed to he p int where use of the pri r ar solvent lushing oil would be hazardous.-

. Inspection of such engines at the conclusion of the. flushing operations has shown them to be substantially free of accumulated gummy residues, as well as of sludge, and to be in the bestof condition to receive a fresh charge of lubrieating-oil;

The preferredcompositionis. as we have said. especially well suited for-use in flushing crankcases of passenger automobiles and light trucks, and other engines which are subjected tothe general kind of service. additional solvent compositions may beprepared from the'sa-me ingredients, within the range in dicated below, for meeting conditions which are peculiar to gasoline and Diesel: engines ofthe; type used inheavy trucks; busses, construction machinery, and the like.

In addition. we find. that the preferred composition. as well. as others. made within-.tlzefiora Wehave found that of machine parts, cleaning tools and dies, and for a wide variety of general industrial purposes. In applications of this general kind, the extreme pressure agent and wax acids soap obviously serve no useful function and may of course be omitted with a corresponding saving in cost.

Having described our invention in its broad form and illustrated it by way of specific example, what we claim as new and useful is:

A solvent composition for flushing engine lubrication systems consisting essentially of about 50 per cent by volume of ortho dichloro benzene, about 19 per cent of cresylic acid, about 30 per cent by volume of naphtha having a boiling range of about 163 to 177 F., about 1 per cent by volume of sulphurized tributyl phosphite containing 15 about 50 per cent sulfur, and about 0.5 per cent by volume of magnesium soap of wax acids.

JOHN D. MORGAN. RUSSELL E. LOWE.

REFERENCES CITED it following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,169,783 Ellis -s Feb. 1, 1916 1,495,005 Dunning May 20, 1924 1,980,043 Ellis Nov. 6, 1934 2,259,872 Baldeschwieler et al. Oct. 21, 1941 2,339,096 Morgan Jan. 11, 1944 2,356,340 Murphree Aug. 22, 1944 

